gpgmailtunl is a filter program that either encrypts an email message using the Gnu Privacy Guard and sends it to another recipient or decrypt an email message and forwards unencrypted to another destination.

It can be used to exchange emails across an open network betweeen two trusted systems.

This program is intended to run from program like procmail or sendmail to create an email tunnel between two systems.
Of course this is not as secure as using gpg as an end user program,
it may be convenient in certain case.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.